Vibration Stop Device

ABSTRACT

A vibration stop device that can prevent a problem caused by intrusion of a pressure contact region of a holding part of the vibration stop device into a recess of a processing region of a work includes a plurality of holding parts for the vibration stop which hold an outer circumferential surface of a columnar work in a process stage under a pressure contact state with pressure supplied from a hydraulic cylinder, and a pressure contact position on the outer circumferential surface is changed by rotation of the work, and an angular range formed by opposite ends of each of the holding parts for the vibration stop is larger than an angular range of the processing region regarding an angular range based on a position of an axis of the rotation.

TECHNICAL FIELD

The present invention is relates to a vibration stop device necessary for stopping vibration of a work in a process stage.

BACKGROUND OF THE INVENTION

Accurate processing on a work in a process stage requires the work to be prevented from vibrating.

The work is divided into a processing region and a non-processing region along a circumferential direction, and in many cases, moves together with a main shaft in a state where a holding part for vibration stop is in pressure contact with an already processed region of the work.

As shown in FIG. 5, in the pressure contact state of the holding part of a prior art, a pressure contact region is too small. Thus, it cannot be avoided to make a partial region of the holding part come into pressure contact.

On the other hands, the pressure contact state causes a problem that the pressure contact region of the holding part intrudes into a region recessed by the processing, in the other words, in a recess, and even if the work is to be rotated along a columnar center axis for the next processing, such rotation is hindered due to the intrusion.

However, in the prior art, no particular countermeasure has been taken for the problem caused by the pressure contact region of the holding part intruding into the recesses that has been formed by the processing.

For reference, Patent Document 1 describes, regarding a camshaft work to be ground, a processing region and vibration stop for the work, nevertheless has no particular description on the relationship between the processing region and the vibration stop.

Patent Document 2 describes both processing on a work and a vibration stop device, but does not describe the problem arising when the pressure contact region comes into contact with the region that has already been processed.

PRIOR ART DOCUMENT Patent Document

Patent Document 1: JP 2005-169530 A

Patent Document 2: JP 2010-99746 A

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

An object of the present invention is to provide a configuration of a vibration stop device that can prevent a problem caused by a pressure contact region of a holding part of the vibration stop device intruding into a recess of a region that has been processed.

Effect of the Invention

To achieve the object, the present invention has the following basic structure:

-   -   A vibration stop device, a plurality of holding parts for         vibration stop holds an outer circumferential surface of a         columnar work in a process stage under a pressure contact state         with pressure supplied from a hydraulic cylinder, and pressure         contact position on the outer circumferential surface is changed         by rotation of the work,     -   wherein an angular range formed by both ends of each of the         holding parts for vibration stop is larger than an angular range         of a processing region regarding an angular range based on a         position of an axis of the rotation.

In the present invention having the basic structure, the pressure contact region of the holding part of the vibration stop device never introduces into the recess in the processing region, and so, the problem in the rotation of the work due to the intrusion can be prevented.

Moreover, in the examples described later, the position of the holding parts can be independently adjusted, whereby the precision error of the work can be easily corrected.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side cross-sectional view of a first embodiment.

FIG. 2 is a side cross-sectional view of a second embodiment.

FIG. 3 is a side cross-sectional view of a third embodiment.

FIG. 4 is a side cross-sectional view of a vibration stop device of an example 1, and also includes a block diagram showing a configuration of an oil pressure supplying device of an example 2.

FIG. 5 is a side cross-sectional view of a configuration of a vibration stop device of the prior art.

DETAILED DESCRIPTION

As described in the basic structure, the present invention has a feature that, regarding the angular range based on a position of an axis of rotation of a columnar work 2, an angular range formed by both ends of each of a holding part for vibration stop 11 is larger than an angular range of a processing region 21.

The basic structure can be embodied in a number of ways. FIGS. 1 to 3 show typical embodiments.

FIG. 1 shows the first embodiment having a feature that a holding part has an arc shaped surface on the pressure contact side, and a radius of curvature of the arc is the same as the radius of the work 2.

In the first embodiment, pressure contact can be done mainly at a non-processing region 22.

Of course a holding part for vibration stop 11 never intrudes into a recess of the processing region 21 that has already been processed.

FIG. 2 shows the second embodiment having a feature that the holding part for vibration stop 11 has an arc shaped surface on the pressure contact side, and a radius of curvature of the arc is larger than the radius of the work 2.

FIG. 3 shows the third embodiment having a feature that the holding part for vibration stop 11 has a flat surface on the pressure contact side.

In the second and third embodiments, the surface of the holding part for vibration stop 11 on the pressure contact side might come into contact with or come close to a surface of the processing region 21, as shown in FIGS. 2 and 3. However, also in these embodiments, as shown in FIGS. 2 and 3, the holding part for vibration stop 11 never intrudes into the recess of the processing region 21 as in the first embodiment. This is because the angular range formed by both ends of each of the holding part for vibration stop 11 is formed to be larger than an angular range of the processing region 21.

As shown in FIGS. 1 to 3, in each of the first, second, and third embodiments, a pair of the holding parts for vibration stop 11 comes into pressure contact with both sides of the work 2, and the two sides of the work 2 are rotatably connected to the pair of the holding parts for vibration stop 11, and a pressure transmission part 12 which is interlocked with a single hydraulic cylinder 31 is provided, such that approaching and separating of the holding parts for vibration stop 11 to and from the work 2 are achieved by changing oil pressure.

In the first embodiment, even when the entire processing region 21 is formed into the recess as shown in FIG. 1, the holding parts for vibration stop 11 are in pressure contact with both sides of the non-processing regions 22 and at least four pressure contact regions are formed. Thus, unlike the conventional technique shown in FIG. 5, the holding part for vibration stop 11 for directly transmitting the oil pressure from the hydraulic cylinder 31 is not required to be provided in addition to the holding parts for vibration stop 11 for sandwiching the work 2 from both sides.

However, in the second and third embodiments, as shown in FIGS. 2 and 3, the holding parts for vibration stop 11 are not necessarily in pressure contact with both sides of the non-processing regions 22. When the depth of the recess of the processing region 21 is very small, the pressure contact is made on two positions of the processing regions 21, and so the pressure contact state is achieved at substantially two points. Thus, as shown in FIGS. 2 and 3, the third holding part for vibration stop 11 that directly presses and comes into pressure contact with the work 2 by the pressure from the hydraulic cylinder 31 may be provided.

The first embodiment does not require the third holding part for vibration stop 11, and thus can achieve a simpler design and lower cost compared with the second and third embodiment.

However, the first embodiment requires the holding parts for vibration stop 11 having radii of curvature respectively corresponding to the various radii of the works 2, and thus is more cumbersome than the second and third embodiment in this point.

Examples are described as follows:

EXAMPLES Example 1

As shown in FIG. 4, the example 1 has a feature that the holding parts for vibration stop 11 are each independently interlocked with a hydraulic cylinder 31, and approaching and separating of the holding parts for vibration stop 11 to and from the work 2 are achieved by changing the oil pressure.

When a precision error occurs in the work 2, the pressure contact state created by a vibration stop device needs to be immediately released, and the processing region 21 where the precision error has occurred needs to be rotated to an operation position on a main shaft side.

In such a case, the conventional technique shown in FIG. 5 and the embodiments shown in FIGS. 1 to 3 require cumbersome control such as an operation of the pressure transmission part 12, and movement of the third holding part for vibration stop 11.

In the example 1, the rotation state can be achieved by immediately releasing, from each of the holding parts for vibration stop 11, pressure supplied from the hydraulic cylinder 31, and the precision error can be quickly corrected.

In many cases, a number of the holding parts for vibration stop 11 and a number of the hydraulic cylinders 31 shown in the example 1 are each three.

Example 2

As shown in FIG. 4, the example 2 has a feature that a relief valve 34 is provided in juxtaposition with the solenoid valve 33 which supplies the oil pressure to the vibration stop device, in a hydraulic circuit that creates the pressure contact state.

Specifically, a hydraulic cylinder 31, a pressure reducing valve 32 for adjusting the pressure, and the solenoid valve 33 for turning ON and OFF transmission of reduced pressure are used as in the conventional technique, and the relief valve 34 in parallel with an oil pressure circuit is further provided.

In the example 2 described above, even if the vibrating state of the work 2 is changed and consequently the amount of pressure required for the pressure contact of the holding part for vibration stop 11 changes by turning ON the relief valve 34, the change in the pressure can be compensated by the relief valve 34 turning on, so that the pressure transmitted to the hydraulic cylinder 31 can be reduced as much as possible.

APPLICABILITY OF THE INVENTION

Thus, the present invention can achieve the vibration stop without the problem of intrusion into the recess of the processing region, and can quickly correct the precision error, and thus is extremely useful.

EXPLANATION OF REFERENCE NUMERALS

-   1 vibration stop device -   11 holding part for vibration stop -   12 pressure transmission part -   2 work -   21 processing region -   22 non-processing region -   3 oil pressure transmission device -   31 hydraulic cylinder -   32 pressure reducing valve -   33 solenoid valve -   34 relief valve -   35 oil pressure supply part 

1. A vibration stop device comprising: a vibration stop device including a plurality of holding parts for a vibration stop for holding an outer circumferential surface of a columnar work in a process stage under a pressure contact state with pressure supplied from a hydraulic cylinder, and wherein a pressure contact position on the outer circumferential surface is changed by rotation of the work, and an angular range around the work which is formed by two opposite ends of each of the holding parts for the vibration stop is larger than an angular range of a processing region of the work based on a position of an axis of the rotation.
 2. The vibration stop device according to claim 1, wherein the holding parts for the vibration stop each have an arc shaped surface on a pressure contact side thereof, and a radius of curvature of the arc is the same as a radius of curvature of the work.
 3. The vibration stop device according to claim 1, wherein the holding parts for the vibration stop each have an arc shaped surface on a pressure contact side thereof, and a radius of curvature of the arc is larger than a radius of curvature of the work.
 4. The vibration stop device according to claim 1, wherein the holding parts for the vibration stop each have a flat surface on a pressure contact side thereof.
 5. The vibration stop device according to claim 1, wherein a pair of the holding parts for the vibration stop comes into pressure contact with two sides of the work, and the two sides of the work are rotatably connected to the pair of the holding parts for the vibration stop, and further comprising a pressure transmission part which is interlocked with a single hydraulic cylinder for approaching and separating of the holding parts for the vibration stop to and from the work by changing oil pressure.
 6. The vibration stop device according to claim 1, wherein the holding parts for the vibration stop are each independently interlocked with a hydraulic cylinder for approaching and separating of the holding parts for the vibration stop to and from the work by changing oil pressure.
 7. The vibration stop device according to claim 6, wherein there are three said holding parts for the vibration stop.
 8. The vibration stop device according to claim 1, further comprising a hydraulic circuit for supplying pressure to achieve the pressure contact, the hydraulic circuit including a relief valve in juxtaposition with a solenoid valve for supplying oil pressure to the vibration stop device. 